Adam McKay’s latest film, Don’t Look Up, tells the story of our response to a comet heading directly for Earth.
One of the film’s main storylines is the battle between two tribes: those who believe in the threat posed by the comet, and those who do not.
In the end, these contrasting beliefs both become irrelevant. And that’s because our beliefs and expectations cannot affect the course of a comet any more than they can change the way the wind blows.
But while this is true of events in the natural world, a growing body of evidence is showing, in new and sometimes dramatic ways, the effect of our expectations and beliefs upon human affairs.
Perhaps the most documented example of this is the placebo effect. This term first entered the medical lexicon in the late 18th century but became more widely acknowledged after the Second World War.
This popularisation is often attributed to the anaesthetist Henry Beecher, who observed that injecting patients with a saline solution they believed to be morphine was 90% as effective as the drug itself, which was in desperately short supply.
Since then, countless trials in areas as diverse as Parkinson’s, pain management, and depression have shown that the placebo effect can account for a significant chunk of the potency of new medicines. Interestingly, in some regions its power seems to have increased in recent decades – a cultural pattern that has emerged in the US, but not in Europe.
But while it is true that positive expectations about a (dummy) pill are often enough to bring about an improvement in our condition, it is also true that negative expectations can have the opposite effect – a phenomenon known as the nocebo effect.
In a recent review of 1,271 clinical trials, for example, researchers found that on average around half of those who received the placebo reported at least one adverse side effect. It seems, in other words, that negative expectations about the possible outcomes of a particular medication are just as important as positive ones.
While the placebo and nocebo effects have been studied for many years in the medical world, much less is known about the impact of our expectations in other areas. But it turns out that expectation-setting might well be a valuable tool in several domains.
Many teachers will be aware of the Pygmalion effect – which describes how teachers’ expectations about a child’s potential can influence their academic outcomes (after the Ancient Greek sculptor who fell in love with his own statue of a woman).
They can be found, too, in our relations with those around us. Robert Putnam has noted, for example, that the more we think we can trust others, the more we display this trust towards them, which over time creates and cements relationships built on mutual confidence.
They can even be found in monetary policy. The Bank of England issues ‘forward guidance’ to help set expectations about the Central Bank’s future actions. This is not just about providing information. The Bank sees it as a critical part of its ‘Monetary Policy Toolbox’ precisely because it knows that the decisions of people making financial decisions will change in response to what they expect the Bank of England intends to do.
What the above examples tell us is that people’s beliefs and expectations can significantly affect the outcome of any situation that involves human beings. That doesn’t include the flight path of a comet. But it does include anything that concerns ourselves and others.
